Comparison of Growth and Water Quality in the Cultivation of Anguilla japonica and Lactuca sativa in Aquaponics with Biofloc and RAS Technologies

Sustainable aquaculture requires innovative systems that enhance production efficiency while minimizing environmental impact. Among emerging technologies, biofloc technology (BFT) and recirculating aquaculture Systems (RAS) are widely adopted for intensive fish culture; however, their integration with aquaponics remains underexplored. This study aimed to compare the growth performance and water quality in aquaponic (AP) systems combining Japanese eel (<i>A. japonica)</i> and caipira lettuce (<i>L. sativa</i>) using BFT and RAS technologies for 28 days. This study compared four aquaculture configurations: BFT, RAS, BFT-AP (BFT with aquaponics), RAS-AP (RAS with aquaponics). Results showed that aquaponics integration seems to be improve the fish growth and apparent feed efficiency. Eels reared in BFT-AP achieved the highest final weight, weight gain, specific growth rate and apparent feed efficiency, which were relatively greater than in BFT, RAS, or RAS-AP systems. The growth of caipira lettuce was markedly enhanced in BFT-AP, with total biomass nearly four times that of RAS-AP. Electrical conductivity and total dissolved solids were relatively higher in BFT-AP than in RAS-AP, indicating nutrient enrichment beneficial for plants. In conclusion, integrating aquaponics with BFT substantially enhanced both eel and production of caipira lettuce. The BFT-AP configuration represents a more efficient and ecologically balanced model for sustainable aquaculture intensification compared with traditional RASs.